1. Field of Invention
This invention relates to animal feed supplements formed as liquid gels and containing a substantial quantity of solid feed nutrients suspended in the gels.
2. Brief Statement of the Prior Art
Sugar and protein containing by-products of the feed industry are commonly used in diets for domestic animals; often added as liquids to the animals' daily feed ration. Phosphates have been added to the supplements as a source of dietary phosphorous; urea has been added to supply non-protein nitrogen; and fats have been included, as described in U.S. Pat. No. 2,793,952. Vitamins have been included in these supplements as described in U.S. Pat. No. 2,807,546.
Most liquid supplements are made by suspending insoluble feed ingredients in molasses with suspension agents such as phospholipids, lecithin, clays, gums and the like. These attempts have found only limited success, as the resultant suspensions cannot retain greater than about 10 weight percent of an insoluble ingredient, such as fat. The suspensions also have limited stability, a problem which is particularly acute when drugs or medications such as monisan are included in the supplement. When settling occurs, as it invariably has in the past, the animals are not provided with a uniform feed ration and imbalances in the feeding program result, causing poor feed efficiency and low gains.
Examples of suspensions of solid feed nutrients and fat in animal feed supplements are described in my prior U.S. Pat. Nos. 4,267,197; 4,804,546; and 4,937,082. The invention disclosed in the '197 patent is the formation of a thixotropic gel carrier for powdered solid feed nutrients and fat by adding a phosphate salt to a sugar solution such as molasses, condensed wheys, and lignin sulfonates to form a stable liquid gel. The maximum amount of fat which can be suspended for adequate storage times with this technique is about 10 weight percent, although greater amounts can be temporarily suspended. The patent cautions against use of wheys which are so concentrated that lactose will precipitate during storage.
The invention disclosed in the '546 patent permits suspension of greater amounts of fats in sugar solutions such as molasses by dispersing melted fat in the sugar solution. The invention disclosed in the '082 patent is a method to form a liquid gel by the addition of phosphoric acid and calcium hydroxide to sugar solutions such as molasses or condensed wheys. This method permits dilution of the liquid gel to sugar contents less than required for the other methods. Gels with increased water contents are desirable because of lower ingredient costs and because greater amounts of other nutrients such as fat or limestone can be suspended in these gels than in more conventional suspensions.
Liquid feed supplements have also been prepared by the addition of water, ammonium polyphosphate and calcium chloride to molasses, as described in U.S. Pat. No. 3,962,484. If the calcium chloride is added to molasses before the ammonium polyphosphate, excessive gelling and precipitation will occur, as reported in depth in: "Calcium Chloride in Liquid Feed Supplements" NFIA Counter Oct. 14-16, 1973, pp 115-129, by Grosso et al, the inventors named in the aforementioned patent.
It is also known that solid feed supplements can be obtained by the addition of certain gelling agents to molasses. This practice has resulted in commercial acceptance of "poured chemical blocks". The poured chemical blocks are either soft blocks formulated with lime and phosphoric acid at an acidic pH (3.0 to 6.5) as described in U.S. Pat. Nos. 4,027,043 and 4,160,041, or hard blocks in which the formulation contains substantial amounts of alkaline additives, usually magnesium oxide, as described in U.S. Pat. Nos. 4,431,675; 4,171,385; 4,171,386; and 4,265,916; New Zealand Patent 170505, Australian Patent 438,073; and U.K. Patent 1,356,954. Hard blocks prepared by the methods of the latter patents have pH values from 9.5 to 10.5.